Screens mounted on vibratory separators are typically used by quarries to separate loose or suspended materials by grade and/or size. The screen typically consists of a woven wire cloth having a plurality of warp wires arranged and configured to form a plurality of openings therein. A plurality of fill or weft wires are woven through the warp wires to maintain the warp wires in spaced relation to each other. Each of the warp and weft wires has a substantially round cross-section. As the screen is vibrated, the material having a smaller size than the openings in the woven wire cloth is passed through the openings in the woven wire cloth, and the material having a larger size than the openings in the woven wire cloth are guided over and off of a top surface of the woven wire cloth onto a pile by the weft wires.
In the above described screen, problems occur in that the material that is to be separated gradually wears down the material of the warp and weft wires thereby altering the dimensions of the warp and weft wires. For example, when the dimensions of the warp wires are altered, the dimensions of the openings in the woven wire cloth are also altered causing the woven wire cloth to improperly separate the material passing through the openings. Additionally, when the dimensions of the weft wires are altered, the weft wires are unable to properly secure the warp wires in spaced relation to each other.
It is therefore desirable to provide a screen for a vibratory separator wherein wear of the warp and/or weft wires of the woven wire cloth is prevented so that the weft wires are able to properly secure the warp wires in spaced relation to each other and the volume of flow of the material through the openings in the woven wire cloth is not impeded.